A Neural Mechanism of Cue-Outcome Expectancy Generated by the Interaction Between Orbitofrontal Cortex and Amygdala.

Taste perception is important for animals to take adequate nutrients and avoid toxins for their survival. Appetitive and aversive behaviors are produced by value evaluation of taste and taste expectation caused by other sensations. The value evaluation, coupled with a cue presentation, produces outcome expectation and guides flexible behaviors when the environment is changed. Experimental studies demonstrated distinct functional roles of basolateral amygdala (ABL) and orbitofrontal cortex (OFC) in value evaluation and adaptive behavior. ABL is involved in generating a cue-outcome association, whereas OFC makes a contribution of generating a cue-triggered expectation to guide adaptive behavior. However, it remains unclear how ABL and OFC form their functional roles, with the learning of adaptive behavior. To address this issue, we focus on an odor discrimination task of rats and develop a computational model that consists of OFC and ABL, interacting with reward and decision systems. We present the neural mechanisms underlying the rapid formation of cue-outcome association in ABL and late behavioral adaptation mediated by OFC. Moreover, we offer 2 functions of cue-selective neurons in OFC: one is that the activation of cue-selective neurons transmits value information to decision area to guide behavior and another is that persistent activity of cue-selective neurons evokes a weak activity of taste-sensitive OFC neurons, leading to cue-outcome expectation. Our model further accounts for ABL and OFC responses caused by lesions of these areas. The results provide a computational framework of how ABL and OFC are functionally linked through their interactions with the reward and decision systems.

Secondary osteoporosis in long-term bedridden patients with cerebral palsy.

BACKGROUND: The aim of the present paper was to investigate 20 pediatric patients with cerebral palsy and secondary osteoporosis and consider the efficacy, influence and index of treatment. METHODS: A total of 10 boys and 10 girls, age 1-16 years (mean 7.6 years) with secondary osteoporosis and cerebral palsy treated for 6 months, were studied. Bone mineral density (BMD) was measured. The bone turnover markers were measured just before and 4 months after treatment or at the time of early discontinuation of treatment. The treatment was classified into two groups: vitamin D (alfacarcidol) only; and with bisphosphonate (risedronate). RESULTS: Monotherapy with alfacarcidol was effective for secondary osteoporosis in children, but when used in combination with risedronate it was even more effective in improving BMD. In the two groups, bone-specific alkaline phosphate (BAP) decreased from pretreatment to post-treatment assessment in all but one case, but there was no significant correlation in the difference in DeltaBAP with DeltaBMD. DeltaBAP assumed changes in BAP in treatment either before or after, and DeltaBMD also assumed changes in BMD. N-telopeptides of type I collagen (NTX)/Cr decreased in all cases. The correlation of DeltaNTX/Cr with DeltaBMD was not significant. The therapy and its efficacy did not correlate to the patients' age, sex, medicine regimen or enteral nutrition. CONCLUSIONS: Risedronate therapy is effective for patients presenting with secondary osteoporosis with cerebral palsy. Moreover, it is desirable to treat patients more aggressively from the early stage because risedronate is not affected by the patients' other factors.

[A case of intractable epilepsy showing frequent gelastic seizures by administration of clobazam].

A 13-year-old boy patient had severe mental retardation and spastic quadriplegia due to fetal distress and hypoxic-ischemic brain damage in the perinatal period. He suffered from West syndrome at the age of 7 months, and subsequently was diagnosed as having symptomatic localization-related epilepsy. His intractable epileptic seizures were not controlled by combination of various antiepileptic drugs. After prescribing nitrazepam and zonisamide for more than 1 year, we added clobazam (CLB), which has been marketed in Japan since 2000, to this combination therapy. After the introduction of CLB, tonic seizures disappeared. However, gelastic seizures laughing with a stiff face and a wry mouth appeared frequently before falling asleep, and sleep disturbance worsened subsequently. It has not been reported previously that gelastic seizures are a side effect of CLB, although irritability and sleep disturbance have been described.